The proposed work is the investigation of time modulated coded apertures and their application to clinical Nuclear Medicine imaging using both an Anger camera and high resolution image intensifier camera. Various spatial and temporal codes will be investigated for optimum signal-to-noise and for optimum tomographic reconstruction. BIBLIOGRAPHIC REFERENCES: Koral KF, Rogers WL, and Knoll GF: Digital Tomographic Imaging with a Time-modulated Pseudorandom Coded Aperture and an Anger Camera. J. Nucl. Med. 16:402-413 819759. Bender M, rogers WL, melvin JW: HSRI High Speed X-ray Cinemattographic System for Biomechanics Research, SPIE Symposium on Effective Utilization of Photographic and Optical Technology to the Problems of Highway Safety, Emissions, and Fuel Economy. Dec. 2-3, 1974. Ann Arbor, Mi. Keyes JW and Rogers WL: Improvement of Digitized Displays, (Abs.) J. Nucl. Med. 16:562 (1975).